Use the On/Off Mode button to select FAN. Then use the +/- button to select either Hi, Lo or Auto.
When using the AC and the fan is in the Hi or Lo setting it will run continuously while the compressor will cycle on and off.
In the Auto mode the fan will cycle on and off as well.

If the fan is set on Hi or Lo while using the furnace the AC fan will run continuously, so be sure to set the fan on Auto when using the furnace.
You can, however, leave the AC fan running while using the furnace to help with condensation problems.

After setting the fan, Use the On/Off Mode button to select COOL for AC use. Use the +/- button to select the thermostat temperature setting.
Use the same procedures for the Furnace.

When using the AC, in the Auto mode the fan will run on high when the room temperature is 5º or higher than the thermostat setting. When the room temperature drops to within 4º or less than the thermostat setting, the fan will stop for a few seconds the start again in the Lo mode.

Hope this helps.

Perfect thanks. This is the same thermostat. I didn't realize there were various FAN settings. I thought it was simply Fan, Cool, or Furnace. I didn't think to check if there were options when Fan was selected.

Worked for me too, was driving us crazy. Went over the to fan setting and changed it to "Au" Just pulled our Sunseeker out for a New Orleans trip and couldn't figure out why the ac fan kept coming on and it didn't last fall. Just bought ours in the fall. I think the thermostat probably went back to a default setting after the battery going dead sitting in storage.

This forum is great - first time using it for our new Surveyor 305. We just had this "problem" this weekend! Believe it or not, in June in PA, we had to run the AC during the day and furnace at night. Couldn't figure out why AC was kicking on. Our thermostat is the same one that GRHODES50 posted. Hopefully this will correct our "problem"! Thanks again!!

Use the On/Off Mode button to select FAN. Then use the +/- button to select either Hi, Lo or Auto.
When using the AC and the fan is in the Hi or Lo setting it will run continuously while the compressor will cycle on and off.
In the Auto mode the fan will cycle on and off as well.

If the fan is set on Hi or Lo while using the furnace the AC fan will run continuously, so be sure to set the fan on Auto when using the furnace.
You can, however, leave the AC fan running while using the furnace to help with condensation problems.

After setting the fan, Use the On/Off Mode button to select COOL for AC use. Use the +/- button to select the thermostat temperature setting.
Use the same procedures for the Furnace.

When using the AC, in the Auto mode the fan will run on high when the room temperature is 5º or higher than the thermostat setting. When the room temperature drops to within 4º or less than the thermostat setting, the fan will stop for a few seconds the start again in the Lo mode.

Hope this helps.

Love this forum! We just had this problem and you were able to solve it for us. Thank you!

I'd like to thank the forum, not because it fixed a problem I had but because it fixed a problem i was about to have and didn't realize it yet. I went out and checked mine, didn't realize it was on high, when I turned the thermostat on to heat it would of done exactly this. So you guys fixed it before it was a problem.

Just wanted to send out a big thank you to everyone who follows and responds to FR problems that are posted. I had similar issue with my AC coming on when I turned on our back furnace and went to the FR Forums site to check to see if anyone had similar problem . Sure enough I found SCOC's post and replys and had my answer. This isn't the first time the forums have helped me out

Use the On/Off Mode button to select FAN. Then use the +/- button to select either Hi, Lo or Auto.
When using the AC and the fan is in the Hi or Lo setting it will run continuously while the compressor will cycle on and off.
In the Auto mode the fan will cycle on and off as well.

If the fan is set on Hi or Lo while using the furnace the AC fan will run continuously, so be sure to set the fan on Auto when using the furnace.
You can, however, leave the AC fan running while using the furnace to help with condensation problems.

After setting the fan, Use the On/Off Mode button to select COOL for AC use. Use the +/- button to select the thermostat temperature setting.
Use the same procedures for the Furnace.

When using the AC, in the Auto mode the fan will run on high when the room temperature is 5º or higher than the thermostat setting. When the room temperature drops to within 4º or less than the thermostat setting, the fan will stop for a few seconds the start again in the Lo mode.

Hope this helps.

I know this is an older post, but wanted you to know I had the same thing happen in my new Crusader 315. The fan was set on high causing both fans to run. Set it on auto and no problem. My first experience with an all digital thermostat. Heading South so switch back and forth between heat and air. Thanks for the help